diff -r a5e56749ca3d -r 3d259e1718ef src/pyams_content/reference/interfaces/__init__.py
--- a/src/pyams_content/reference/interfaces/__init__.py	Fri Oct 12 14:33:03 2018 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,42 +0,0 @@
-#
-# Copyright (c) 2008-2015 Thierry Florac <tflorac AT ulthar.net>
-# All Rights Reserved.
-#
-# This software is subject to the provisions of the Zope Public License,
-# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
-# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
-# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
-# FOR A PARTICULAR PURPOSE.
-#
-
-__docformat__ = 'restructuredtext'
-
-
-# import standard library
-
-# import interfaces
-from pyams_content.interfaces import IBaseContent
-from zope.container.interfaces import IContainer
-
-# import packages
-from zope.container.constraints import containers, contains
-
-
-class IReferenceInfo(IBaseContent):
-    """Base reference interface"""
-
-    containers('.IReferenceTable')
-
-
-class IReferenceTable(IBaseContent):
-    """Reference table interface"""
-
-    containers('.IReferenceTableContainer')
-    contains(IReferenceInfo)
-
-
-class IReferenceManager(IBaseContent, IContainer):
-    """References tables container"""
-
-    contains(IReferenceTable)